JP2003234437A - Resin cast type electric apparatus with direct connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin cast type electric apparatus with a direct connector free from a crack on its cast resin in the vicinity of the direct connector even if there arises expansion or contraction in the cast resin thereof due to a temperature change. <P>SOLUTION: An electric apparatus body is accommodated in a case 2, a mounting unit 4 of the direct connector 1 is mounted on a mounting unit 3 of the opening 2a of the case 2, and a cast resin 5 is filled in the case 2. An adhesive 8 having a lower elastic modulus than the cast resin 5 is applied to portion where an inner face of the case 2 opposes the mounting unit 4 of the direct connector 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin casting with a direct connector in which a casting resin is filled in a case in which a direct connector is attached to an opening of a case accommodating an electric equipment body. Shape electric device.

[0002]

2. Description of the Related Art Conventionally, an electric equipment body such as a battery charger main body using a power element is housed in an aluminum case such as a battery charger used in a two-wheeled vehicle or the like, and is poured into the case. In a resin casting electric device filled with mold resin, a wire harness is used for electrical connection with the outside, and it is pulled into the case through a rubber grommet and electrically connected to the electric device main body. The structure in which the case is filled with the casting resin is common.

In such a resin cast type electric device, if a resin having physical properties very similar to the linear expansion coefficient of the aluminum case is selected as the casting resin, expansion and contraction due to temperature change is a rubber molded product, grommet. Since it is transmitted to the wire harness via the cable, it is alleviated by the expansion and contraction of the grommet, and no problem has occurred.

However, recently, space saving, waterproofing,
Due to the market needs for cost reduction, resin cast type electric equipment with direct connector as shown in FIGS. 4 to 6 has been used. In this case, FIG. 4 is a bottom view of the resin casting type electric device with the direct connector,
5 is a plan view of FIG. 4, and FIG. 6 is an enlarged view of portion B of FIG.

In this resin casting electric device with a direct connector, the direct connector 1 which is a resin molded product is directly connected to the opening 2a of the aluminum case 2 and to the convex mounting portion 3 of the opening 2a of the aluminum case 2. The concave mounting portion 4 of 1 is fitted and mounted, the terminals of the direct connector 1 are electrically connected to the electric device body in the aluminum case 2, and the casting resin 5 is filled in the aluminum case 2 in such a state. The aluminum case 2 has a structure in which a plurality of cooling fins 6 are provided on the outer surface of the aluminum case 2. In this case, as the casting resin 5, an epoxy resin having physical properties very similar to the linear expansion coefficient of the aluminum case 2 is selected. The aluminum case 2 is provided with a mounting hole 2b.

[0006]

However, in the conventional resin casting electric equipment with a direct connector, the linear expansion coefficient of the direct connector 1 is different from the linear expansion coefficient of the aluminum case 2 or the casting resin 5, and therefore, The internal stress of the casting resin 5 increases due to the expansion and contraction of the casting resin 5 due to the temperature change of the electric equipment main body such as the main body of the battery charger using the power element, and the aluminum case 2 shown in FIG. There is a problem that a crack is generated at the casting resin 5 filled in the narrow gap 7 where the inner surface and the concave mounting portion 4 of the direct connector 1 face each other, and the crack grows to cause dielectric breakdown. .

As a means for solving this problem, there is a method of using a urethane resin having a low elastic modulus as the casting resin 5, but since the urethane resin has a low thermal conductivity,
When a large amount of heat is generated like a main body of an electric device such as a main body of a battery charger using a power element, there is a problem that a diode or a thyristor as a power element exceeds its allowable temperature and is destroyed.

Further, since the urethane-based casting resin 5 has a large linear expansion coefficient, stress is applied to the soldering portion which is arranged at the upper portion and which joins the printed circuit board of the electric device body and the power device diode chip or thyristor chip. May cause cracks in the soldered portion.

To bond the aluminum case 2 to the heat sink on which the power device diode chip or thyristor chip is mounted, epoxy resin is required to secure heat dissipation, but the layers above and below the epoxy resin are different. In order to carry out the work of casting the resin, different filling equipments must be installed, and there is a problem that the curing time of the resin becomes long.

An object of the present invention is to provide a resin casting electric device with a direct connector which does not crack in the casting resin near the direct connector even if expansion and contraction occur due to temperature change.

[0011]

According to the present invention, a main body of an electric device is housed in a case, a mounting part of a direct connector is mounted on a mounting part of an opening of the case, and a terminal of the direct connector is electrically connected to the main body of the electric device. It is intended to improve a resin casting electric device with a direct connector, which is electrically connected and whose case is filled with the casting resin.

In the resin cast electric device with a direct connector according to the present invention, an adhesive having a lower elastic modulus than the cast resin is applied to a portion where the inner surface of the case and the mounting portion of the direct connector face each other. .

In such a resin casting electric device with a direct connector, when expansion and contraction due to temperature changes are repeated, the resin casting is applied to a narrow portion where the inner surface of the case and the mounting portion of the direct connector face each other. Since an adhesive with a low elastic modulus is applied, the displacement caused by the difference in the linear expansion coefficient between the case and the casting resin and the direct connector can be absorbed by this adhesive, and the casting resin will not crack. Can be avoided.

Further, it is not necessary to use a urethane type resin having a low elastic modulus as the casting resin, and an epoxy resin or the like having a good heat dissipation property can be used. Therefore, a urethane type resin having a low heat conductivity can be used for the power element. It is possible to avoid breaking beyond the allowable temperature.

Further, according to the present invention, stress acts on the soldering portion of the power element due to the temperature rise accompanying the use of the urethane resin having low thermal conductivity, and cracks are generated in the soldering portion. This can be avoided by using a casting resin such as epoxy resin having good heat dissipation.

Further, according to the present invention, it is not necessary to fill different kinds of resins in the case, so that it is not necessary to install different filling equipment, and the curing time of the resin can be shortened.

Further, if the main body of the electric device is constructed by using the power element, the temperature rise becomes high. However, in the present invention, since the casting resin such as epoxy resin having good heat dissipation can be used without any problem, It is possible to avoid problems caused by the rise.

When the case is an aluminum case, the coefficient of linear expansion is close to that of epoxy resin, which is a casting resin, and the heat dissipation performance is good.

If the casting resin is an epoxy resin,
The linear expansion coefficient is very similar to that of the aluminum case, the heat dissipation is good, and the problems caused by the casting resin can be solved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 show an example of an embodiment of a resin casting electric device with a direct connector according to the present invention. FIG. 1 is a resin casting type with a direct connector of this example. 2 is a vertical sectional view of FIG. 1, and FIG. 3 is an enlarged view of part A of FIG. The parts corresponding to those in FIGS. 4 to 6 described above are designated by the same reference numerals.

In the resin-casting electric equipment with a direct connector of this example, the resin is more elastic than the casting resin 5 such as epoxy resin in the narrow gap where the inner surface of the aluminum case 2 and the mounting portion 4 of the direct connector 1 face each other. A rubber adhesive 8 having a low rate is applied.

A heat sink 9 is fixed to the ceiling surface of the aluminum case 2 by an adhesive 10 such as an epoxy resin. The diode chip 11 and the thyristor chip 12 are attached to the heat sink 9 by soldering. A printed circuit board 13 is arranged in parallel with the heat sink 9 in the aluminum case 2, and the diode chip 11 and the thyristor chip 12 are electrically connected to the printed circuit board 13 by soldering. The printed circuit board 13 is fixed to the direct connector 1 with screws 14.

The terminals of the direct connector 1 are electrically connected to the printed board 13. In this state, the aluminum case 2 is filled with a casting resin 5 such as an epoxy resin having physical properties close to the linear expansion coefficient of the aluminum case 2 and good heat dissipation. Particularly, in the case of the aluminum case 2, it is preferable to use an epoxy resin having a linear expansion coefficient very similar to that of the aluminum case 2 as the casting resin 5.

In this example, the electric device body 15 is constituted by the heat sink 9 to which the diode chip 11 and the thyristor chip 12 are attached and the printed circuit board 13.

In such a resin casting electric device with a direct connector, when expansion and contraction due to temperature changes are repeated, a narrow portion where the inner surface of the aluminum case 2 and the mounting portion 4 of the direct connector 1 face each other is formed. Cast resin 5
Since the adhesive 8 having a lower elastic modulus is applied, the displacement caused by the difference in linear expansion coefficient between the aluminum case 2 and the casting resin 5 and the direct connector 1 can be absorbed by the adhesive 8. It is possible to prevent the mold resin 5 from cracking.

Further, it is not necessary to use a urethane resin having a low elastic modulus as the casting resin 5, and an epoxy resin or the like having good heat dissipation can be used. Therefore, the urethane resin having a low heat conductivity is used as the power element. Can be prevented from being destroyed above its allowable temperature.

Furthermore, stress is applied to the soldering portion of the power element due to the temperature rise caused by the use of the casting resin 5 made of urethane resin having low thermal conductivity, and cracks are generated in the soldering portion. , Casting resin 5 with good heat dissipation, such as epoxy resin
Can be avoided by using.

Further, if the electric device body 15 is constructed by using a power element, the temperature rises high, but in the present invention, the casting resin 5 such as epoxy resin having good heat dissipation can be used without any problem. It is possible to avoid the problems caused by the temperature rise.

When the case 2 is an aluminum case with the cooling fins 6, the linear expansion coefficient is close to that of the epoxy resin, which is the casting resin 5, and the heat dissipation of the cooling fins 6 is high. The presence can further improve the heat dissipation performance.

When the casting resin 5 is an epoxy resin, the linear expansion coefficient is very similar to that of the aluminum case 2 and the heat dissipation is good, so that the problems caused by the casting resin 5 can be solved.

Further, it is not necessary to fill different kinds of resins in the case 2, so that it is not necessary to install different filling equipment, and the curing time of the resins can be shortened.

The case 2 may not have the cooling fins 6 depending on the heat generation temperature of the electric device body 15.

The electric equipment main body 15 housed in the case 2 is, for example, a battery charging apparatus main body using a power element for rectifying the output of a magnet type AC generator to supply electric power to a load. The present invention is not limited to this, and may be an ignition coil or the like using a power element that ignites the internal combustion engine.

[0034]

As described above, in the resin casting electric device with the direct connector according to the present invention, when expansion and contraction due to temperature change are repeated, the inner surface of the case and the mounting portion of the direct connector are injected into a narrow portion. Since an adhesive with a lower elastic modulus than the mold resin is applied, the displacement caused by the difference in the linear expansion coefficient between the case and the casting resin and the direct connector can be absorbed by this adhesive, and the casting resin will not crack. Can be avoided.

Further, it is not necessary to use a urethane type resin having a low elastic modulus as the casting resin, and an epoxy resin or the like having a good heat dissipation property can be used. Therefore, the urethane type resin having a low heat conductivity can be used for the power element. It is possible to avoid breaking beyond the allowable temperature.

Further, it is possible to prevent cracks from being generated in the soldering portion of the power element due to stress acting on the soldering portion of the power element due to the temperature rise accompanying the use of the urethane type resin having low heat conductivity. It can be avoided by using a casting resin such as a resin.

If the main body of the electric device is constructed by using the power element, the temperature rises higher. However, in the present invention, casting resin such as epoxy resin having good heat dissipation can be used without any problem, It is possible to avoid problems caused by the rise.

Further, according to the present invention, it is not necessary to fill different types of resins in the case, so that it is not necessary to install different filling equipment, and the curing time of the resin can be shortened.

When the case is an aluminum case, the coefficient of linear expansion is close to that of epoxy resin, which is a casting resin, and the heat dissipation performance is good.

If the casting resin is an epoxy resin,
The linear expansion coefficient is very similar to that of the aluminum case, the heat dissipation is good, and the problems caused by the casting resin can be solved.

[Brief description of drawings]

FIG. 1 is a bottom view showing an example of an embodiment of a resin casting electric device with a direct connector according to the present invention.

FIG. 2 is a vertical sectional view of FIG.

FIG. 3 is an enlarged view of a portion A of FIG.

FIG. 4 is a bottom view of a conventional resin cast-type electric device with a direct connector.

5 is a plan view of the resin cast type electric device with a direct connector shown in FIG. 4. FIG.

FIG. 6 is an enlarged view of a B portion of FIG.

[Explanation of symbols]

1 Direct connector 2 Aluminum case 2a opening 2b Mounting hole 3 Convex mounting part 4 Concave mounting part 5 Cast resin 6 cooling fins 7 gap 8 Adhesive with low elasticity 9 heat sink 10 adhesive 11 Dahod chip 12 Thyristor chip 13 printed circuit boards 14 screws 15 Electric device body

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Yamaguchi             3744 Ooka, Numazu City, Shizuoka Prefecture             In the company (72) Inventor Takuma Ayuzawa             3744 Ooka, Numazu City, Shizuoka Prefecture             In the company F-term (reference) 4M109 AA02 CA02 EA02 ED01 EE02                 5E322 AA01 AA03 AB09 EA07 EA10                       FA05

Claims (4)

[Claims] 1. An electric device body is housed in a case, a mounting part of a direct connector is attached to a mounting part of an opening of the case, and a terminal of the direct connector is electrically connected to the electric device body. In a resin casting electric device with a direct connector in which the case is filled with a casting resin, an elastic modulus is lower than that of the casting resin in a portion where an inner surface of the case and the mounting portion of the direct connector face each other. Resin cast electrical equipment with a direct connector coated with adhesive. 2. The resin cast electric device with a direct connector according to claim 1, wherein the electric device main body is configured by using a power element. 3. The resin cast electrical device with a direct connector according to claim 2, wherein the case is an aluminum case with a cooling fin. 4. The resin cast type electrical device with a direct connector according to claim 3, wherein the cast resin is an epoxy resin.